In over my head, help a newbie out!

[icallow]

So I recently fell upward into an analyst position at work, and while there's a big push towards Power BI, apparently a significant chunk of our data lives on Cognos Analytics. From what I've been able to gather, someone set up some reports pre-covid and people have just been using those reports ever since. The guy who set them up left the company a while ago, and nobody knows how to do anything with this EXCEPT run those reports. I'd like to get a handle on it.

Unfortunately, I am a very small cog in a very large machine so I don't have access to stuff like setting up my own data modules (I am not trained in data science or whatever, I'm a techy guy with google), and the data I DO have feels like it's all over the place and not labeled particularly well.

Do you folks have any links that might be helpful to me as a newbie, trying to wrap my head around how this is supposed to work? Tips and/or tricks for massaging the data into legible reports? I'll take anything at this point.